The Assessment Of Road Tunnel Ventilation Systems

In 1990 and 1995, PIARC published the calculation methodology and the emission factors for road tunnel ventilation design. An update of the existing PIARC methodology was necessary, as the emission standards of the vehicles were becoming more stringent and hence the vehicles cleaner. The old version described the emission situation up to the year 1995. This document has been produced by Working Group 2 of the PIARC Technical Committee on Road Tunnel Operations in the framework of its activities btween 2001 and 2003. Due to a steady tightening of emission laws for vehicles and changes in the risk assessment of tunnel fire, some design data may need constant updating. In this publication, new design information and some references are given for sizing longitudinal and transverse ventilation systems.

The ventilation system is an important element for the safety of a tunnel, as well as its investment and operating costs. Investors, operators and designers of road tunnels bear a responsibility for the safety of persons, as well as for important investment decisions. The new Road Tunnel Ventilation Compendium fosters understanding of basic aspects of ventilation in the context of tunnel safety, describes the actual state of the art and shows how to design and realise safer tunnels, at lower costs, with reliably functioning systems.

This book illustrates a new quantitative risk analysis model for road tunnels that is capable of evaluating the role of infrastructure measures, equipment and management procedures as prescribed by EU Directive 2004/54/EC. The risk assessment draws on the typical F-N curves of societal risk, evaluated with the help of event tree analysis, vehicle queue formation dynamics, and users’ egress and tenability models. In addition, the model considers the reliability of the safety measures. The work provides essential guidance on the following aspects: how a quantitative model can be implemented to evaluate risk in road tunnels; how to build an event tree for the accident scenarios considered; how to simulate the vehicle queue formation; how to simulate the evolution of accident scenarios; and how to simulate the users’ egress. Given its scope and depth of coverage, the book will be of interest to all engineers whose work involves fire protection and safety in tunnels, all persons engaged in safety and transport engineering or risk analysis for road tunnels, as well as public and private bodies involved in the application of Directive 2004/54/EC.

This book contains twenty-one original papers and one review paper published by internationally recognized experts in the Atmosphere Special Issue "Recent Advances in Urban Ventilation Assessment and Flow Modelling", years 2017–2019. The Special Issue includes contributions on recent experimental and modelling works, techniques, and developments mainly tailored to the assessment of urban ventilation on flow and pollutant dispersion in cities. The study of ventilation is of critical importance, as it addresses the capacity with which a built urban structure is capable of replacing the polluted air with ambient fresh air. Here, ventilation is recognized as a transport process that improves local microclimate and air quality and closely relates to the term “breathability”. The efficiency with which street canyon ventilation occurs depends on the complex interaction between the atmospheric boundary layer flow and the local urban morphology. The individual contributions to this Issue are summarized and categorized into four broad topics: (1) outdoor ventilation efficiency and application/development of ventilation indices, (2) relationship between indoor and outdoor ventilation, (3) effects of urban morphology and obstacles to ventilation, and (4) ventilation modelling in realistic urban districts. The results and approaches presented and proposed will be of great interest to experimentalists and modelers, and may constitute a starting point for the improvement of numerical simulations of flow and pollutant dispersion in the urban environment, for the development of simulation tools, and for the implementation of mitigation strategies.

TRB’s National Cooperative Highway Research Program (NCHRP) 415: Design Fires in Road Tunnels information on the state of the practice of design fires in road tunnels, focusing on tunnel fire dynamics and the means of fire management for design guidance.

Tunnels and Underground Cities: Engineering and Innovation meet Archaeology, Architecture and Art. Volume 9: Safety in Underground Construction contains the contributions presented in the eponymous Technical Session during the World Tunnel Congress 2019 (Naples, Italy, 3-9 May 2019). The use of underground space is continuing to grow, due to global urbanization, public demand for efficient transportation, and energy saving, production and distribution. The growing need for space at ground level, along with its continuous value increase and the challenges of energy saving and achieving sustainable development objectives, demand greater and better use of the underground space to ensure that it supports sustainable, resilient and more liveable cities. The contributions cover a wide range of topics, tunnel inspection analysis, via risk assessment for maintenance planning and civil engineering constraints on tunnel ventilation and safety, to CFD simulations of longitudinal ventilation of a road tunnel. The book is a valuable reference text for tunnelling specialists, owners, engineers, archaeologists, architects, artists and others involved in underground planning, design and building around the world, and for academics who are interested in underground constructions and geotechnics.